﻿TED STATES DEPARTMENT OF AGRICULTUR 



DEPARTMENT BULLETIN No. 1355 



WasWngton, D. C. 



November, 1925 



FOOD HABITS OF THE VIREOS: 



A Family of Inseciivorous Birds 



By Edvv^ard A. Chapin, formerly Assistant Biologist, Division of Food Habits 

 Research, Bureau of Biological Survey ' 



CONTENTS 



Page 



Economic relations 1 



Black-whiskered vireo 3 



Red-eyed vireo 4 



Philadelphia vireo 10 



The warbling vireos 13 



Yellow-throated vireo 15 



Page 



The blue-headed vireos 18 



The white-eyed vireos 21 



The Hutton vireos- 23 



The Bell vireos .- 25 



Gray vireo . 27 



ECONOMIC RELATIONS 



During the summer almost anywhere in the United States at least 

 one species of vireo, and usually more than one, is to be found flitting 

 about in the trees or shrubbery. In the eastern and central parts of 

 the country the common species is the red-eyed vireo, which is con- 

 sidered the most abundant of all species of woodland birds. Others 

 more or less common in the East are the white-eyed, warbling, and 

 yellow-throated vireos, and in the far West there is another form of 

 the warbling vireo that is abundant. The Philadelphia, the blue- 

 headed, the Hutton, and the Bell vireos are found more or less 

 locally. The black-whiskered vireo in the United States is found only 

 in Florida, and the gray vireo is confined to the southwestern portion 

 of the country where it is not at all common. One other species, the 

 black-capped vireo (Vireo atricapillus), is very rare in the United 

 States, and as no stomachs have reached the collection of the Bio- 

 logical Survey nothing can be said concerning its food habits. 



Though in general the food items of all the vireos are very similar, 

 their proportions vary in the diet of different species. For instance, 

 the food of the red-eyed vireo is made up of about seven-eighths 

 animal matter and one-eighth vegetable, whereas that of the yellow- 

 throat contains vegetable matter only to the extent of one-fiftieth 

 of the total, and that of the Bell vireos apparently to an even less 

 extent. Caterpillars make up an eigfith of the food of the Hutton and 

 more than a third of the warbling vireos. Bugs arc seldom eaten by 

 the Philadelphia vireo and amount to but a tenth of the food, whereas 



' Doctor Chapin has been transferred from the Biological Survey to the Zoological Division o( tho Bureau 

 • Aniinul Industry since preparing this report. 



50209— 25t 1 1 



